Cardio-respiratory studies in chronic mountain sckeness (Monge's syndrome)

Abstract

SUMMARY. Comparisons with 14 normal, younger, male native residents of La Paz showed that 20 patients with Monge's syndrome have significantly higher mean body surface areas, hemoglobin, resting tidal volumes [VT (BTPS)], and resting minute volumes [VE (BTPS)]. If [VE (BTPS)] is subdivided into its components of alveolar [VA (BTPS)] and dead space ventilations [VDS (BTPS)], it becomes apparent that the former is significantly smaller and the latter much larger in the Monge patients than in the controls. Further differences emerge in that means of physiological dead space, PA-aCO₂ and PA-aO2 gradients are increased in the Monge group. Alveolar hypoventilation in the Monge group is evidenced by an elevated mean PaCO₂; a lower mean pH of 7.349, a PaO₂ of 48.1 mm Hg, compared with 57.7 mm Hg in the normals; and a mean arterial oxygen saturation of 82.8% versus that of 89.7%in the latter. Simultaneous surface scanning of the right upper and lower lung zones, using a central venous injection of 131 IHSA (human iodinated serum albumin), showed a reduction of total isotope activity in the right upper - zones of the Monge group, both in the sitting and recumbent positions. A perfusion anomaly of the upper lung zones is postulated to explain the increase physiological dead space and which appears to be related to a structural difference in the right upper lobe pulmonary arteries contrasted with those in the right in the lower lobes.